Additive and subtractive manufacturing technologies enable computer designs, such as CAD files, to be made into three dimensional (3D) objects. 3D printing, also known as additive manufacturing, typically comprises depositing, curing, fusing, or otherwise forming a material into sequential cross-sectional layers of the 3D object. For example, fused deposition modeling techniques, which are generally disclosed in U.S. Pat. No. 4,749,347 and U.S. Pat. No. 5,121,329, among others, include melting a filament of build material or print material and extruding the print material out of a dispenser that is moved in the x-, y-, and z-axes relative to a print pad. The print material is generally deposited in layers in the x- and y-axes to form cross-sectional layers that are stacked along the z-axis to form the 3D object.
Commercially available three dimensional printers, such as the Cube® 3D Printer manufactured by 3D Systems of Rock Hill, S.C., use a print material or ink that is jetted or extruded through a print head as a liquid to form various printed parts. In some instances, the print material is deposited onto a print pad (or onto a “raft” of support material disposed on the print pad), which can result in the formation of a bond between the extruded print material and the surface of the print pad (or between the surface of the raft and the surface of the print pad). However, after the print process is complete, the bond is generally broken and the printed part is removed from the print pad.
A weak bond between the extruded print material (or the support material, if a raft is used) and the surface of the print pad can cause the extruded print material to separate from the print pad prematurely. Such separation can lead to a failed print process and/or to imperfections in the printed 3D object. In contrast, a strong bond can prevent the extruded print material from separating from the print pad prematurely but may also make it difficult to remove the printed 3D object and any support material from the print pad following completion of the print process. Further, this difficulty can require a user to employ a hand tool such as a scraper to separate the printed 3D object from the print pad, which can lead to damage to the printed 3D object and/or the surface of the print pad.
In addition, because print pads are often reusable, it can be desirable to remove all of the extruded print material or support material of a previous print process prior to beginning a new print process. In some instances, such removal can be tedious and time consuming as well as damaging to the print pad. Therefore, a need exists to improve the printing of 3D objects to provide accurate parts, models, and other 3D objects that are easily and safely removed from the print pad.